Voice channel control of wireless packet data communications

ABSTRACT

A data session with a wireless device ordinarily cannot be initiated from the network side because the wireless device has no predetermined IP or other network address. Methods are disclosed for instead causing the wireless unit to initiate a data session with a target destination, thereby obviating the IP addressing problem. A voice call is first initiated by a requester application to a remote wireless unit. The requester transmits a request message to the remote wireless unit via the wireless voice channel using in-band techniques; preferably including a payload in the polling message that identifies the target destination. In response, the remote wireless unit initiates a packet data session with the target destination.

COPYRIGHT NOTICE

© 2005 Airbiquity Inc. A portion of the disclosure of this patentdocument contains material that is subject to copyright protection. Thecopyright owner has no objection to the facsimile reproduction by anyoneof the patent document or the patent disclosure, as it appears in thePatent and Trademark Office patent file or records, but otherwisereserves all copyright rights whatsoever. 37 CFR § 1.71(d).

TECHNICAL FIELD

This invention pertains to data communications via wirelesscommunications networks, and more specifically it relates to use of thevoice channel to trigger a network initiated data session such as an IPsession.

BACKGROUND OF THE INVENTION

Data transfer services in the wireless domain are known and certainlystill evolving. Examples include SMS (short messaging service) and otherSS7 control channel services. They can be used, for example, for textmessaging. They do not affect the voice channels, but offer very limitedbandwidth, so the amounts of data transferred are quite limited.

The WAP (Wireless Application Protocol) specifications and softwareoffer some improved services. For example, they can be implemented toprovide limited Internet access to a mobile unit. (We use the term“mobile unit” herein to refer broadly to any device with wirelessconnectivity, including without limitation a cell phone, PDA, laptopcomputer, palmtop, motor vehicle, etc.). The WAP services, however,require that the mobile unit itself be WAP enabled, and that thewireless carrier network also be WAP enabled. Thus, wireless carriershave to deploy and maintain WAP gateways at the edges of the network toprovide WAP services. Some mobile units, and some networks or geographicareas may not be WAP enabled, so these services would not be availablefor data communication.

One approach to wireless data transfer that does not require changes inthe wireless network infrastructure, although it requires specificimplementation at both endpoints of a session, is the use of “in-band”data transfer. As the name implies, this technique transfers data in thevoice channel, using carefully selected and timed audio frequency tones.(Commonly, wireless data transfer services do not use the voice channelat all.) In-band or voice channel data transfer can be done with littleor no interruption of a voice conversation. Details of in-band signalingare explained in U.S. Pat. Nos. 6,144,336; 6,690,681 and 6,493,338 allincorporated wherein by this reference. These types of in-voice-channeldata communications have two primary advantages: the wireless voicechannel is reliable, and the technique works transparently acrossnetworks and carriers throughout the country and beyond. The data simplypasses transparently through the voice service, as it “looks” likevoice. However, in-band signaling provides only a very low bandwidth upto around 400 bps. That makes it almost useless for transferringsignificant amounts of data.

Higher bandwidth wireless data services are rapidly becoming availablethroughout the world. These services operate over dedicated datachannels, not the voice channels. The newer specifications, so-called“3G” or third generation wireless technologies, while not yet widelyimplemented, promise packet data rates as follows, according to IMT-2000standards:

-   -   2 Mbps for fixed environment    -   384 Mbps for pedestrian (i.e. slow-moving mobile unit)    -   144 kbps for vehicular traffic

One problem, however, with virtually all wireless data services, is thedifficulty in accessing those services in a network “polling” type ofapplication. Polling (or “pulling data”) here refers to contacting amobile unit to pull or retrieve digital data needed by a requester. (The“requester” typically would be an application program.) Preferably, anauthorized requester should be able to poll remote mobile units, andfetch data, without manual user intervention at the remote location. Inother words, a polling process should be able to be completelyautomated, although for some applications it can be advantageouslyinitiated by a user at the requester end.

To illustrate, a wireless automated inventory control system may seek topoll units, say trucks or tanks, to learn their present location, fuelsupply, operator ID, etc. A packet data connection, for example an IPconnection, cannot be established with a mobile unit from the networkside (we call this “network initiated”) using prior technology, becausethe mobile device has no predetermined IP address. Rather, an IP addressis dynamically assigned to a mobile unit only if and when it initiates asession to an IP network. Accordingly, a user application cannot poll aremote mobile unit to establish a packet data transfer session usingknown technologies.

A system has been suggested for IP addressing of GPRS mobile terminalsthat purportedly would enable TCP/IP connection without a phone call.That proposal recognized that there are not enough IP addressesavailable (under the current Ipv4 regime) to assign one to everywireless terminal. The proposal calls for a combination of PublicAddresses (registered with public routing tables) and Private addresses,not to be routed on the public Internet. Rather, the private (IP-like)addresses would only to be used within a GPRS operator's own network.This would require network address translation (NAT) facilities and isgenerally impractical. Even if implemented, such a scheme does not solvethe problem that the mobile (or wireless) terminal address is unknown,and is not publicly discoverable in a convenient way.

The need remains for a convenient and effective way to poll a remotemobile unit, that is, to request a packet data session, for uploading ordownloading data via the wireless network, without changing the wirelesscarrier infrastructure and in a manner compatible with existing packetdata networks and protocols such as IP.

SUMMARY

In accordance with one embodiment of the present invention, acombination of in-band or voice channel signaling together with packetdata services is employed to overcome the lack of a predetermined IPaddress of a mobile unit. A voice call is established between arequester and the remote mobile unit. A short polling message istransmitted in the voice channel from the requester using in-banddigital data transmission (“IBS”). The request message includes in itspayload data that identifies (directly or indirectly) a target resourcesuch as a URL or IP address. The mobile unit responds by initiating awireless packet data session with the indicated target resource whichmay be, for example, a server system.

This new approach of using the voice channel signaling to enable anetwork initiated data session will solve the existing problemassociated with assigning an IP address (Simple IP and Mobile IPassignment for both IPv4 and IPv6) to a mobile device and do so in atimely and more efficient manor.

Presently the existing cellular infrastructure does not allow mobiledevices to pre-register their IP address with the cellular data network,instead it must be assigned to the mobile device by the cellular datanetwork when a mobile device first initiates a request for a datasession using a Simple IP protocol, or the mobile device must initiatean IP address discovery process using the Mobile IP protocol. In ethercase the cellular data network does not know of the routing location ofthe IP address for a mobile device until the mobile device firstinitiates a data session.

The core data network of any data enabled cellular network can use thisunique invention to initiate a data transfer session, which we will calla Network Initiated Data Session (NIDS) and is described as follows:

According to one aspect of the invention, in-band signaling methods andapparatus and employed to “push” a request to a mobile unit or “node”.We call this a Mobile Terminated (MT) request. (The mobile device is ofcourse in-band signaling enabled, meaning essentially that it can sendand receive digital data through the voice channel of a wirelessnetwork.)

The receiving mobile unit (mobile node) detects—and triggers the mobiledevice (or other system coupled to the mobile device) to initiate a datasession with the cellular network using an available data channel, notthe voice channel, to transmit data to a specified (or default)destination.

When a request is made of the mobile device, by using voice channelsignaling, the network can initiate a data session between the mobiledevice and any network or internet entity at any time using the voicechannel of the cellular network, or any other radio frequency derivedaudio channel where voice channel signaling functions. Due to the realtime speed and quality of service of in-band (voice channel) services, adistinct time savings and reliability advantage can be made over anyother approach for network initiated data sessions. These advantages areof paramount importance for public safety and security applications.

The present invention is also independent of any digital cellulartechnology and is not tied to any individual cellular carrier's voice,data, or messaging service, which is also unique and advantageousoffering greater cellular coverage capabilities when compared toexisting approaches.

Additional aspects and advantages will be apparent from the followingdetailed description of preferred embodiments, which proceeds withreference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a simplified high-level diagram illustrating operation ofrepresentative embodiments of the invention.

FIG. 2 is a messaging diagram showing principle interactions among nodesinvolved in an embodiment of the invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Reference is now made to the figures in which like reference numeralsrefer to like elements. For clarity, the first digit of a referencenumeral indicates the figure number in which the corresponding elementis first used.

In the following description, certain specific details of programming,software modules, user selections, network transactions, databasequeries, database structures, etc., are provided for a thoroughunderstanding of the embodiments of the invention. However, thoseskilled in the art will recognize that the invention can be practicedwithout one or more of the specific details, or with other methods,components, materials, etc.

In some cases, well-known structures, materials, or operations are notshown or described in detail in order to avoid obscuring aspects of theinvention. Furthermore, the described features, structures, orcharacteristics may be combined in any suitable manner in one or moreembodiments.

FIG. 1 is a simplified high-level diagram illustrating certainembodiments of the methodology of the present invention. Referring toFIG. 1, a requestor application program can be provided on a suitablecomputer 100. The request or polling application can be activated by auser as needed or preprogrammed for automatic operation at scheduledtimes. The computer system 100 is coupled to a telephone line which mayinclude a conventional telephone 102 and in any event is connected via104 to the public switched telephone network PSTN 106. This connectioncan be, for example, an ordinary telephone land line as is commonly usedfor voice calls. It could also be part of a larger enterprise systemthat may involve a PBX (not shown), or it may be a wireless telecomconnection.

A wireless carrier network 108 is connected to the PSTN 106 for handlingwireless call traffic, the details of which are well known. The wirelessnetwork 108 includes a series of base stations which include antennasand wireless transceivers, generally referred to as a cell tower 110.Transceivers are mounted atop the cell tower 110 for two-way wirelesscommunications with various wireless mobile devices such as a cell phone112 or PDA 114. The base station antennas need not literally be mountedon a tower. In urban areas, in particular, they are more commonlyaffixed to buildings.

In accordance with the invention, a requestor or a requestor applicationexecuting on computer 100 initiates a voice telephone call, via the PSTNor wireless, directed to a remote mobile unit such as the cell phone112. The connection from the requestor application need not be hardwired to the PSTN but could itself be a wireless telephone link. Therequester system 100 also may have access to the Internet 122, typicallythrough an ISP (internet service provide) 124. The connection to the ISPcould take any of various forms, for example utilizing cable or the PSTNnetwork, as are known.

According to a preferred embodiment of the invention, a method isprovided for polling the remote wireless unit as follows: First, therequester system 100 initiates a voice call to the remote wirelessstation. This of course requires that the telephone number of the deviceis known. Other kinds of mobile devices, such as the PDA 114 or even amotor vehicle 116 can include apparatus that is configured to interactwith the wireless network as if it were a cell phone, although it maynot actually include a microphone or a speaker. For example, devices canbe configured to automatically answer a wireless call, and provide thecontrol channel signaling to emulate answering a cell phone. Once avoice call is established between the requestor 100 and the remotewireless unit 112, the requestor system 100 transmits a digital requestmessage to the remote wireless terminal via the wireless voice channelon which the voice call is established. In other words, the digitalrequest message is sent “in band” through the use of audio frequencytones that are arranged so that they will pass through the voice channelunobstructed.

The request message preferably includes a payload that identifies atarget resource. In the remote wireless unit, for example 112, 114,apparatus or software is implemented that will respond to the digitalrequest message by initiating a packet data session with the targetresource identified in the request message. By “packet data session” wemean a data transfer session that utilizes one or more of the dataservices provided by the wireless carrier, as distinguished from voiceservices.

The target resource may be, but is not limited to, the requester system100 itself. In other words, the wireless terminal 112 may be instructedto initiate a packet data session back to the requestor system. Thatsession would traverse link 120 from the wireless network infrastructureto the Internet 122 and thence to the requestor 100 via the ISP 124. Asnoted, this process can be automated by implementing suitable softwareat the requestor 100 and at the wireless unit 112 so that it can occurwithout user action at either end of the packet data session.

The target resource can be identified in the request message by apredetermined identifier, such as a simple alphanumeric name or code.The wireless terminal software can perform a look-up in memory todetermine a corresponding URL or IP address. Alternatively, the targetURL or IP address can be included in the request message itself.

The target resource need not be the requesting system 100. In onealternative embodiment, it could be a server 130 which is coupled to theInternet through an ISP and configured to perform data collection,utilizing standard packet data session protocols such as the Internetprotocol. The target may be a web server suitably configured to interactwith the mobile unit.

In other embodiments, the request message payload can include variousdelivery parameters, in addition to identification of a target resource.The delivery parameters might include, by way of example and notlimitation, a preferred packet data service, a packet data rate, and/ora priority parameter. These parameters can be recovered from the messagepayload by the wireless terminal software and it can initiate aresponsive packet data session in accordance with those parameters. Forexample, in the case of a relatively low priority parameter, theapplication software might select a data service or time of day toinitiate the packet data session that is lower performance but incurslower cost.

Referring again to FIG. 1, the tanker truck 116 is merely illustrativeof a wide variety of mobile assets, including but not limited to motorvehicle assets, that could participate in the present system, assumingthey are outfitted with a wireless unit as explained above. FIG. 1 alsoshows a second wireless base station tower 136 illustrating that thepacket data session need not involve the same base station, or even thesame wireless carrier, as that which carried the request message via thevoice channel. The requested packet data session could occur through asecond wireless network 138 which is also coupled to the Internet via140. And again, the packet data session could be established with anytarget resource, including but not limited to the requestor application100 or a separate server 130.

In other embodiments of the invention, a live user or operator at acomputer 150, having access to the Internet, could poll one or moreremote wireless units to request a data transfer. For example, a user atsay a public safety location such as a 911 emergency call taker, couldaccess a web server (not shown) which has voice call telephone accesssuch as 104. Through the means of a suitably programmed web pageinterface (using, for example, cgi scripting or the like), a user at 150could initiate a request message which would take the form of a voicecall from the web server, through the PSTN and the wireless network asdescribed above, to a remote or mobile unit. The request message couldinclude identification of the call taker center at 150 as the targetresource to deliver requested information via a packet data session.

The present invention is not limited to downloading data from thewireless terminal to the requestor. The requested packet data sessioncould also be used to download information to the wireless terminal.

FIG. 2 is a messaging diagram that further illustrates principalfeatures and characteristics of certain embodiments of the invention.

Referring to FIG. 2, a signaling or message flow diagram furtherillustrates methodologies in accordance with the present invention.Beginning with “time interval A” and initiating application 208essentially places a voice call out to the mobile telephony device 204.As noted above, the initiating application could be a softwareapplication deployed on a computer or on a server and it may or may notnecessarily require a conventional telephone. It does require access tothe wireless network, directly or through the PSTN. The telephonydevice, in turn, makes a voice call through the cellular network 202which in turn makes a wireless call to the mobile unit 200. The mobileunit answers the call, thereby establishing a voice channel “connection”back to the telephony device 204. Once that voice call is established,the initiating application, at “time interval B” transmits a requestmessage in the voice channel to the mobile device 200. Optionally, themobile device may respond with an acknowledgement message in the voicechannel.

Referring now to “time point C,” responsive to the request message, themobile terminal 200 initiates a data network connection, which traversesthe cellular network 202 and establishes a packet data session via theIP network 206. Here, the target or destination resource is coupled tothe IP network 206. The IP network in turn responds to the mobile node200 at “time point D” and then, as indicated at “time point E” a packetdata session is established between the mobile node 200 and the IPnetwork or target 206. “Time point F” indicates that the IP resource maynot be the ultimate recipient of the data, but rather, it could beconfigured to forward that data to an ultimate destination address whichmay be, but is not limited to, the initiating application 208.

The process used by the core data network, internet application, orstand alone device to initiate a data session using aqLink begins withthe establishment of a circuit switch voice channel connection to themobile device. This can be accomplished by any means made available tothe initiating application or device.

It will be obvious to those having skill in the art that many changesmay be made to the details of the above-described embodiments withoutdeparting from the underlying principles of the invention. The scope ofthe present invention should, therefore, be determined only by thefollowing claims.

1. A method of polling a remote wireless unit, the method comprising:establishing a voice call between a requester and the remote wirelessunit, the voice call established on a wireless voice channel of atelecommunications network; after the voice call is established betweenthe requester and the remote wireless unit, transmitting a digitalpolling message from the requester to the remote wireless unit via thewireless voice channel; including a payload in the digital pollingmessage that identifies a target resource, wherein the digital pollingmessage is transmitted in-band over the wireless voice channelseparately from an out-of-band control channel, and wherein the payloadis represented by audio frequency signals selected to pass through thewireless voice channel unobstructed by vocoders operating in thetelecommunications network; and in the remote wireless unit, responsiveto the digital polling message, initiating a packet data session withthe target resource.
 2. The method according to claim 1, wherein thetarget resource is a predetermined IP network location, and wherein theaudio frequency signals are used to identify the target resource to theremote wireless unit.
 3. The method according to claim 1, wherein thetarget resource is specified by a predetermined identifier carried inthe payload, the predetermined identifier represented by the audiofrequency signals.
 4. The method according to claim 1, wherein thetarget resource is specified by a URL carried in the payload, the URLrepresented by the audio frequency signals.
 5. The method according toclaim 1, wherein the target resource is specified by an IP addresscarried in the payload, the IP address represented by the audiofrequency signals.
 6. The method according to claim 1, furthercomprising pulling data from the remote wireless unit via a wirelessnetwork packet data session, wherein the wireless network packet datasession is automatically initiated by the remote wireless unit inresponse to receiving the digital polling message and without manualuser intervention at the remote wireless unit, and wherein the data ispulled from the wireless unit over the wireless network packet datasession without manual user intervention at the remote wireless unit. 7.The method according to claim 6, wherein the polling message payloadfurther comprises at least one delivery parameter, the deliveryparameter represented by the audio frequency signals.
 8. The methodaccording to claim 7, wherein the delivery parameter is one of aselected wireless network packet data service, a data rate and apriority parameter, the selected delivery parameter represented by theaudio frequency signals.
 9. The method according to claim 6, wherein thepolling message payload identifies a type of data to be transmitted inthe wireless packet data session.
 10. The method according to claim 9,wherein the type of data to be transmitted is data indicating a locationof the remote wireless unit.
 11. A wireless communications system,comprising: a computer coupled to a telecommunications network; apolling requester application executable on the computer for sending apolling message through a wireless voice channel of thetelecommunications network to a wireless remote unit, wherein thepolling message is represented by audio frequency signals selected topass though the wireless voice channel unobstructed by vocodersoperating in the telecommunications network; a wireless remote unithaving wireless telecommunications capability for receiving a voicecall; the remote unit configured to recover the polling message from thevoice channel; and the remote unit configured to initiate a data sessionresponsive to the recovered polling message.
 12. The wirelesscommunications system of claim 11, wherein the polling requesterapplication transmits a payload in the polling message.
 13. The wirelesscommunications system of claim 12, wherein the polling requesterapplication identifies a target network resource in the payload.
 14. Thewireless communications system of claim 12, wherein the payload includesindicia of at least one data session parameter.
 15. A method ofuploading data from a wireless unit, the method comprising: receiving avoice call in the wireless unit via a wireless telecommunicationsnetwork; recovering a request message from the voice call, wherein therequest message is encoded as audio frequency signals transmittedin-band in a wireless voice channel of the received voice call, whereinthe audio frequency signals are received over the wireless voice channeland separately from an out-of-band control channel; and responsive tothe recovered request message, initiating a data session between thewireless unit and a target resource for uploading data using a digitalwireless data service.
 16. The method of uploading data from a wirelessunit according to claim 15, further comprising downloading data to thewireless unit in the data session.
 17. The method of uploading data froma wireless unit according to claim 15, wherein the data session isinitiated with a predetermined network resource in response to receivingthe request message.
 18. The method of uploading data from a wirelessunit according to claim 17, wherein the network resource is identifiedby a URL or an IP address in the request message.
 19. The method ofuploading data from a wireless unit according to claim 15, wherein therecovered request message includes a network address of the targetresource.
 20. The method of uploading data from a wireless unitaccording to claim 15, wherein the wireless unit comprises a cell phone.21. A wireless unit, comprising: a transceiver configured to receive avoice call via a wireless telecommunications network; communicationcircuitry coupled to the transceiver, the communication circuitryconfigured to recover a request message from the voice call, wherein therequest message is encoded as audio frequency signals transmittedin-band in a wireless voice channel of the received voice call, whereinthe audio frequency signals are received over the wireless voice channeland separately from an out-of-band control channel; and thecommunication circuitry further configured to initiate a data sessionbetween the wireless unit and a target resource for uploading data usinga digital wireless data service, wherein the data session is initiatedaccording to the request message.
 22. The wireless unit of claim 21,wherein the communication circuitry is further configured toautomatically initiate the data session in response to recovering therequest message from the received voice call, wherein the data sessionis initiated independently of any local user inputs to the wirelessunit.
 23. The wireless unit of claim 22, wherein the communicationcircuitry is further configured to automatically upload data identifiedby the audio frequency signals over the data session independently ofany local user inputs to the wireless unit.